Field of the Invention
The present disclosure relates to the field of medical imaging and in particular to clinical imaging of tissue such as skin or other bodily tissue, with or without lesions, for reference and analysis.
Description of the Related Art
Conventional methods of clinical imaging employ methods where there is little or no control over the light source, exposure, orientation to the subject or the optical characteristics of the image. Images are used to document the visible characteristics of a scene and are used in diverse fields such as remote sensing, dermatology and forensics. In some cases, a measurement tool is introduced into the imaging field of view to allow for approximate correlation of the captured images to a linear scale. In photogrammetry time scale images are compared and corrected for spectral and spatial frequency distributions. This is often a laborious process. Spectral artifacts are difficult to correlate in a time series of digital images due to variation in angles of the source light and variation in optical axes and the impacts of ambient conditions. Photogrammetric observations use tracking of parameters such as position, distance from the subject and time, to ensure the optical angles of reference can be used in image correlation and rectification. Rectification is often complicated by the three dimensional characteristics of the scene. In medical imaging, coordinate systems can be used to spatially relate subject matter to a standard, such as the Talairach atlas.
Applicant is not aware of any standard by which photographic or spectroscopic images of human tissue can be used to repeatedly establish the tissue specific molecular optical characteristics of all subjects at different times, with different optical conditions. U.S. Pat. No. 6,738,652 discusses the optical thickness of the skin as a ratio of protein to fat spectra. The correlation of an image time series using conventional techniques is complicated by the inability to accurately compensate for exact changes due to variations in the ambient conditions.
Therefore there is a need for technical approaches in clinical imaging that allow clinicians to quickly acquire skin images without having to concern themselves with the complex optical considerations that surround the rectification and registration of images.
This background information is provided to reveal information believed by the applicant to be of possible relevance to the present application. No admission is necessarily intended, nor should be construed, that any of the preceding information constitutes prior art against the present application.